DEVELOPMENT TREND OF STRAIGHT WELDED PIPE MILLS BOTH AT HOME AND ABROAD

The paper involves analysis of the development trend of straight welded pipe mills both at home and abroad. Also discussed are the characteristics of two formation processes, i. e. roll-forming and row-roll forming and the operation and process/equipment problems of the existing dozen of ERW straight welded pipe mills imported from abroad. It is emphasized that units of the mill for high （medium ） frequency treatment, ultrasonic detection, shearing/butt-welding and.o.f.oll forming have to be imported,while such units as flying shearer,horizontal spiral looper, hydrostatic tester and end-facing/chamfering machine can be made at home